From graves and medieval drawings to climate-controlled exhibition space and strict deadlines, Exeter Cathedral presented SSH Conservation site manager John Mullins MCIOB with plenty of challenges.
Exeter Cathedral is a Grade I-listed building. Its cloisters were destroyed during the civil war in the 17th century. Our project involved the rebuilding of the east section of cloister.
The Victorians planned the reconstruction of the medieval cloisters and started building in the south-east corner of the original cloister footprint in 1887, but ran out of money. The Pearson building, named after gothic revival architect John Loughborough Pearson, remains in this location.
We were effectively carrying on where the Victorians left off, by reinstating the east cloister, joining the south aisle of the cathedral with the Victorian Pearson building.
Archaeological excavation at the start of the project revealed the stone foundations of the cloisters. This medieval stonework would form the base of the new cloister wall.
Graves, skeletons and wall footings were discovered during the excavation phase – which, along with other finds, put us behind programme. But the stonework was successfully accelerated by adding masons. At the later stages of the build there were five small teams of two or three masons working on each bay of the cloister wall.
The design of the wall meant the stonework progressed quickly. Five new buttresses were formed in stonework around new reinforced concrete columns. The new cloister wall consists of 70 tonnes of Doulting stone, with 20 tonnes of Marnhull stone for the window and door surrounds and tracery, along with 45 tonnes of limecrete wall core, and 8 tonnes of Portland stone for the parapet wall copings, plus various stainless-steel ties, reinforcements and wind posts.
Prefabricated frame
The overall design of the new stone tracery windows and doors was derived from records of the original medieval stonework and the tracery in the Pearson building that was a Victorian interpretation of this. The new windows and doors have modern mouldings and glass that is in keeping with the times.
One milestone was reaching roof height and the installation of the oak roof frame. This includes seven main beams at 12in x 15in, weighing half a tonne each, and smaller subsidiary beams.
The specialist subcontractor sourced the oak from France – from the suppliers that were providing oak for the rebuilding of Notre‑Dame. The frame was prefabricated in its workshop according to point cloud survey information. Even the scribing-in of beam ends was done off site, and installation was completed in two days using an 18-tonne crawler crane.
Another milestone was the installation of the new walkway floor consisting of reclaimed Purbeck stone removed from the quire of the cathedral during previous works.
Numbered floor slabs were meticulously set out to a pattern by the architect, with Blue Lias ledgers to show the position of the graves. This was installed on a limecrete slab with stainless steel mesh reinforcements and underfloor heating. The floor was quite difficult to install but looks great, and forms an interesting junction between new and old stonework.
The project’s final stages involved coordinating M&E installations with the completion of construction tasks. Two lifts were installed, as well as lighting and audio systems, heating and ventilation.
Special exhibition areas
Part of the reordering of the Pearson building involved installing general and special exhibition areas on the first floor, both controlled with mechanical ventilation systems. The special area has security shutters, interlocking doors and is void of sunlight. Rare Anglo-Saxon treasures from the cathedral archives will go on display here in April 2025.
One of the most challenging parts of the project was the programme. There were many variations to replan for, and subcontractors to organise. Among unexpected discoveries was a stone vault that had to be partially removed to form an opening for the lift shaft in the Pearson building.
I learned that it was important to delegate as much as possible to make time to review the programme.
Liaising with the cathedral was also essential. Tasks and deliveries had to be scheduled according to events, and quiet times observed. It was very important that the project completed before 2 November 2024 in time for the enthronement of the new Bishop of Exeter – a once-in-a-decade event.
As the date drew nearer, the work was accelerated by increasing site hours. It completed on the evening of 1 November, thanks to a concerted effort from the team on site.
